Enchant Blade - Cast at the start of your turn. Place this card on one of your Weapons. This Weapon is now considered a Magic Object and adds an additional 1 to your Strength during battle.
What is the duration for this spell? Does it last for the remainder of the game? May this spell be used on Magic Objects (for example, making the Runesword a +2 Weapon)? If the enchanted object is obtained by another character, does the enchantment remain?
No, because the Runesword is a Magic Object not a weapon. (Look at the card). The card states weapon, not Magic Object.
The Runesword is a Weapon. "Weapon" is a keyword that may appear on Object and Magic Object cards. The "weapon" keyword governs Objects that may add a bonus in Battle or Psychic Combat and only one Weapon may be used during an attack (unless a Character has an ability to allow, such as the Warrior).
To summarize, the Runesword is a Magic Object with the Weapon keyword. My question was whether a Magic Object Weapon (using Runesword as example) could be the recipient of the Enchant Blade spell. I guess so, but a FAQ entry seems forthcoming on the subject, so perhaps not.